stall speed problem

[nastynotchback1]

i can not get this thing to stall higher then 5600rpm.I have the stage 6 adjustable clutch with new red springs maxed out,ztr 1500 torque spring and i had to mix 5.0 and 5.5 gram weight in the Dr pulley variator.the roller weight is funky but it's what the quad wants right now.I have a trackside pipe on the way so i know these clutch settings will be changing but i can't figure out why the stall speed want go any higher.any ideas?

[bignasty]

Pm sent

[EthansDad]

make sure you have the orange/red springs on the stage 6, not the white ones. that alone should get it to 6500-7k. don't forget belt length effects stall. ultimately its the speed of the rear pulley, not the variator/motor that determines stall.

so if you have a longer belt, it will be spinning the rear pulley slower per every revolution of the variator. the initial ratio of variator to rear pulley is in the neighborhood of 3.5:1, and will go up/down a bit based on belt size. so if your motor is turning 5600 rpms, the rear pulley is turning at 1600 rpms. a longer belt will turn the rear pulley just a bit slower (since you've effectively made the rear pulley bigger by having a belt ride up higher on the pulley), which will delay stall.

Also, as a "plan B" you can take your stage 6 clutch shoes apart and grind some equal weight off each shoe. its centrifugal force going on here, so if the shoes are lighter, it will take more rpms to make them fling out.

-EA

[jerkyboy]

Are you runnig any of the weights in the shoes? If you are try removing them, if thats not helping try lighter rollers for the hell of it. Make sure the belt goes all the way down in the variator.

[nastynotchback1]

No weights in the shoes.Started with 3.75 rollers and it would not pull up.I have changed rollers a dozen times working my way up to what i have in it now.The belt is a 787 and the variator is shimmed so the belt can go farther down.

[jerkyboy]

Try a 109 bell

[nastynotchback1]

Originally posted by jerkyboy
Try a 109 bell

never thought about that.i will try it out.thanks

[nastynotchback1]

The 109 did not really help.Went back to the 3.75 rollers with new 2000 shoe springs maxed out and a 1500 torque spring(ztr).it will stall 6000-6100 now but i am getting belt travel before it gets to the stall speed.

[jerkyboy]

Somthing must be wrong cause if I run a 109 bell I can get the stall all the way to 8000 rpm. Make sure you have the red springs
in it, the red and orange are very close in color. Also are the springs new?

[nastynotchback1]

they are red and i just installed them yesterday after this problem came up.

[jerkyboy]

In your first post you said the springs were maxed out Im assuming you were at the very last white line. You ever try a 780
belt. With this clutch I have never seen this problem before.
Maybee take it aprt and make sure the shoes arent getting hung up.

[nastynotchback1]

past the last line.adjusted as far as i can go with them.I have a 780 belt but i figured that would make it stall less.

[jerkyboy]

Try it what you got to lose at this point, only takes a minute to change the belt

[EthansDad]

the shorter belt will make it stall sooner. if its stalling at 5600 with a 787 belt, will likely stall at 5200/5400 with a 780. the shorter belt drops farther into the rear pulley and spins the rear pulley a bit faster per revolution of the front pulley.

I think something is wrong with your stage 6 clutch with a stall that low. you can get a stock / yamasida clutch with 2k koso shoe springs to stall north of 7500 easy.

-EA

[nastynotchback1]

I have a stock one already set-up i may install and see what happens.thanks

[nastynotchback1]

Okay guys it appears that the springs i have may be orange but if they are they are real close to red.Will the red be a really bright red or darker blood red color?

[TTracer#22]

They are Bright RED they make the difference.

[nastynotchback1]

Originally posted by TTracer#22
They are Bright RED they make the difference.

so the darker red must really be orange?

[nastynotchback1]

Got it to stall 6900 after changing to a used ztr1500 i had but still going up in roller weight.was at 3.75 now at a mix of 4.0/5.0 gonna make a few more adjustments and see what happens.

[jerkyboy]

In a earlyer post I asked about the color of the springs cause there real close in color. Somthing still seems odd, If I crank those springs down to the first line It will raise the stall to around
7900 rpm which isnt realy what you want.

[nastynotchback1]

Originally posted by jerkyboy
In a earlyer post I asked about the color of the springs cause there real close in color. Somthing still seems odd, If I crank those springs down to the first line It will raise the stall to around
7900 rpm which isnt realy what you want.


They look red to me but i am thinkin they are the orange.All i can do is order some red springs and see if they are the same as what i have now.The pipe is killin it at the moment so as soon as i get the new pipe here i can start all over again lol

[EthansDad]

the roller weights really should not effect stall. if they are, then what is happening is the heaver weights are making the CVT shift BEFORE stall (losing first gear) and making your rear pulley spin faster i.e. bigger weights make it stall sooner due to preshift. that is another problem....shimming the variator helps there.

this is for your 70, yea? what are you targeting for stall. as a reference, I have the stall on our 70 with an over range kit set at around 7200 using a stage 6 clutch and its happy there. might even be able to bring it down a bit with out any noticeable difference. not sure if you'd want to stall a built 70 much higher than that, gonna generate a lot of heat if you do. if its still not launching like you want, you might have another problem, just a thought. maybe wrong tranny gears, final gearing, etc that is holding back the launch.

-EA

[nastynotchback1]

6500-7000 is what i was shooting for and i got that now.The problem i have is that with a 3.75 roller the belt will not travel up any further than alittle past half.I put 5.0 in it just a few minutes ago and it runs up to about an 1/8th from the top but it will not turn more than 10,200.It will run up to right at 9700 and sit there a few seconds and then on up to 10200 and thats it.I am thinking at this point i need to wait on the new pipe to get here or just load it up and bring it to you.




Originally posted by EthansDad
the roller weights really should not effect stall. if they are, then what is happening is the heaver weights are making the CVT shift BEFORE stall (losing first gear) and making your rear pulley spin faster i.e. bigger weights make it stall sooner due to preshift. that is another problem....shimming the variator helps there.

this is for your 70, yea? what are you targeting for stall. as a reference, I have the stall on our 70 with an over range kit set at around 7200 using a stage 6 clutch and its happy there. might even be able to bring it down a bit with out any noticeable difference. not sure if you'd want to stall a built 70 much higher than that, gonna generate a lot of heat if you do.

-EA

[EthansDad]

you said you are using a dr. pulley variator, yea? I have not had good luck with those. only had one bike that liked it. What I noticed about the dr. pulley is the ramp angles (what the rollers ride in) is fairly linear compared to others that are more greatly slopped or hyperbolic. a linear ramp angle like the dr. pulley makes the weights roll up slower initially, then faster later on in the rpms. and that is generally not good (at least on our bikes). I want the rpms to build fast, then slow down right at the sweet spot for shifting. that comes with a ramp angle that starts flat, then gets progressively sloped upwards.

do you have a stock yamasida variator to try? those have a more progressive ramp angle and what I'd expect is that your stall will remain, but with a lighter weight (3-4g) you will get more belt travel, and it will shift at a higher rpm (like at 11.5/12 VS 10k now). what ever you try, its the variator that controls when and at what rpm the bike shifts.

remember goal of CVT = shift at max HP. if you make max HP at 12k rpms, and you are shifting at 10k, you are missing out on the goodness.

in an ideal world if you pinned a bike from stand still, the rpms would climb to stall, then the bike takes off in first gear until it reaches peak HP rpms, then starts to shift.

[nastynotchback1]

yeas i do have a stock one,several of them lol i will try one of those tomorrow.Going to the house now.thanks

[joe0718]

I think you might be right with the pipe holding you back. I had a 50 production that had a Koso 1500 torsion spring and 4.2 to 5.0 rollers to get it to run good and have decent belt travel. It still only turned 10200 rpm though. If I lowered the roller weights the rpm would go up but it killed the belt travel. I ended up getting a different pipe that turned 12500 rpm and good belt travel with around 3.5 rollers. In the end I went to a stock 90 pipe different clutch set up and it was its fastest at 11000 rpm.